&SIGNAL: PLOT-FIELD: functions


charges

  The induced charges are computed by first calculating a
  drift line of the requested type and then integrating the
  internal product of drift velocity and weighting field
  over the drift line. The charge thus obtained is multiplied
  with the charge of the particle that has been drifted.

  The charge should be +1 or -1 for a particle drifting from
  the read-out electrode to another conductor and 0 for a
  particle that drifts between conductors that are not read
  out.

  The charge induced over a given path should, apart from the
  sign, should not depend on the type of particle that drifts.
  However, in the presence of a magnetic field, electrons and
  ions will in general follow different paths, may therefore
  end up at different points, and hence induce different charges.

  Charges are expressed in multiples of the electron charge.

status_code

  The status codes are the numeric status codes:

  ----------------------------------------------------------------------------
  Status                End of drift line             Numeric code
  ----------------------------------------------------------------------------
  Left area             Left the drift area           -1
  Too many steps        More than MXLIST steps        -2
  Abandoned             Various faults                -3
  Hit a plane           Hit an equipotential plane    -4
  Left drift medium     Entered a dielectricum        -5
  Left mesh             Left the finite element mesh  -6
  Hit an X wire         Hit a wire of type X          1 to MXWIRE
  Hit an X wire replica Hit a replica of an X-wire    MXWIRE + (1 to MXWIRE)
  Hit an X solid        Ended in a solid of type X    2*MXWIRE + (1 to MXSOLI)
  Unknown               Other cases (shouldn't occur) other
  ----------------------------------------------------------------------------

times

  The times are the total drift time for particles of the
  selected type from the position at which the function is
  to be evaluated until the particle leaves the AREA, hits
  an electrode, exceeds the maximum number of steps, is
  abandoned etc.

  The times are expressed in microsec.

weighting_field

  The weighting field is the field with which the drift
  velocity of a moving charge is multiplied to obtain the
  current induced in the various electrodes.

  There is one such field per electrode or per group of
  sense wires.

  This field is computed by setting the read-out electrode
  to unit voltage and earthing all other conductors.

  The unit of the weighting field is 1/cm.

Keyword index. Formatted on 10/11/98.